New DuetWifi Install: Why filament unloads at the end of print?

I've only owned my first printer, Tevo Tarantula, for 2 months after upgrading to DuetWifi. Thanks for everyones hard work, this thing rocks!

In Cura I'm still specifying the Prusa i3 with flavor Reprap as I did with the MKS electronics and Marlin but never had this problem. At the end of every Cura sliced prints the head remains on the print while the heaters turn off. The extruder then runs for maybe 10 minutes retracting the filament. When it completes the cold "hotend" breaks itself free from the print and returns as it should. Below is the end code of a print where this happens. I thought it was cause by the line right after TIME_ELAPSED, G1 F1500 E4941.13188, but I commented that out in another test and the problem persisted. Any thoughts how to fix this? I've tried to switch to Slic3r but I have alot of work to do with that to get the prints Cura is providing without barly any tweeks. I'm not seeing this problem with Slic3r and no responses from UltaMaker on this.

All coordinates from now on are relative to the last position. Note: RepRapFirmware latest revision firmware uses M83 to set the extruder to relative mode: extrusion is NOT set to relative by ReprapFirmware on G91: only X,Y and Z are set to relative. By contrast, Marlin (for example) DOES also set extrusion to relative on a G91 command, as well as setting X, Y and Z.

All coordinates from now on are relative to the last position. Note: RepRapFirmware latest revision firmware uses M83 to set the extruder to relative mode: extrusion is NOT set to relative by ReprapFirmware on G91: only X,Y and Z are set to relative. By contrast, Marlin (for example) DOES also set extrusion to relative on a G91 command, as well as setting X, Y and Z.

Yes, that's the problem. The OP needs to add M83 just after G91 in his slicer end gcode. The G91 is still needed because there is a G1 Z0.5 move as well.